Friction clutch



Jan. 8, 1946. T. H. BRIGGs ET AL FRICTION CLUTCH Filed Feb. 18, 1944 .L mw

N K., ma n l u @m WIA@ w a M A om Nm M w n u L .Nwwmm Z172 U @zaofs Patented Jan. 8, 1946 en ys' OIF HC E v v t'naaaszt,`

, FRGTION Curren- Thpmasylisryfrisss andz-Walzterlienrr.. Briggs,

1 SonsLimi-td, .Brlingham, England 'Application February 18, 1944; SralN.- 522,92173 'in .Great Britain March` 31, 1943 f T2 Claims. (cli k leze-sli).

This invention has for its object to provide an improved `frictioxi cluteh yoff the multi-plate type, and particularly for in the transmission mechanisms. or moto'r cycles-.-

Inv the. accompanying sheetofY izplanator-y drawings: I

'Figure l is afsect-'ional side elevation-of. a fric'- .tion .clutch constructed" in accordance with the invention, and Figure `2 is 'a-fplan lof a part oiV the .clutch shown Elgure l.

Figures 31 and `1l: are similar. views to Figure k1 illustrating respectively two-modifiedforms of the-invention,- and'aFigurefisi-a- .plan of" a part offthefclutchshownin Figure 4.. p l

In carrying the invention into -effectgas shown -lnmgures 1 andi; 'Wei-employ a Ispindle a which serves as the driven' (rorodr-ivingf) member. On this lsplndle'isfreely mountedfa clutch member b, vand on'the latterwi's secured or formed a driving'.- (or ldri-ven) sprocket wheel c. The clutch member-- Iris. in theformof a plateV having extending from'. `one -sidelofit a peripheral Aflange d; Within the space .enclosed by thelflang'e d' of fthe clutch rneinberb =.(hereinaftrtermed the outenclutch 'inem'bew` is arranged' another clutch nfleinberv e. .(hereinaftertemed the inner vclutch memberiwhich ls-securedto the spindle" and which isformed with a prlpheralfilahge-f, the latter being separated from the flange on the Aouter.'clutc'hmem-ber- 'by an annular space.

this annular space arearrangedf a', plurality of annular friction plates in', arrangemntbeing such that vthe plate's alternate with vthe plates fi: Outer radi-al1 .projections las-7G on Athe friction platestt engage grooves for slots als-vin` in the-flange dief the outerliclutch memberb; and.. inner radial projections-as n; on. the .otherifrictionplates :i engage .slo ts;.or'.. grooves as oin' `the flange fior the nlutc-hmember .42. Also the 'plate 7' which is situate@ nea-metto; the main portion of the outer; clutch member bircives endwise support from a shoulder p on the ange f of the inner clutch member e. At the side of the inner clutch member e remote from the main portion of the outer clutch member b is arranged a pressure plate q which is shaped to accommodate and enclose the adjacent end of the spindle a. The periphery of the pressure plate q carries another annular friction plate r having inward radial projections as s engaging grooves as t in the periphery of the pressure plate. This annular plate r receives endwlse support from a shoulder u on .the periphery of the pressure plate, and is arranged to act on the adjacent side of the friction plate assembly i, y', Preferably andas shown the friction plates z' carry pads asi-2 `afp-any convenient -frictionmat'erialfagainstwhich the 'adjacent facesof 'the friction vplates fand fr can bear: f

the portion of fthesliindle. `ttflyin'g between i -r clutch linem1ber. aand the presslilre` plate 1 `isefre'ely mounted 4a cam plate .12,- and immediately.alongside-.the cam plate there is keyed tothe *spindle acam Icollarlw which is supported 'endwise` lt` y...a-r'rutA .or pair of.r nuts screwedy on to 'the adaeent .endlofthe spindle. The Icam plate e slidabiy-conneeted to the pressure plate vq by one or more (preferably three) pinsV as 5y se-` cured. at one end to one. of A.these plates and slidf ablethrough aj-holeorfholeswin thcother., Also thecam plate-.uisconnected 'to the-pressure plate .qF-bua plurality'. .of- (preferably three). additional pins as' surrounded. by strong helical springs as '3; Each f2.1is.secure`d atoneend. to the. cam .plate v, andJhasfscrewedon. itsl other .or outer .end an adjustablecollar-A. Thersprings 3 on` the pins -Zf bearat .oneend against. the` corresponding. collars #andata theother end against abutments on the pressurefplate 11. -Also the. springs 3. are en- .ciosedv .by` .tub arY .housings '5. Shaving. at their inner` vends..in-ternal:` anges 6i which form the above 1meritionediabutments forfthe springs, and at: theirmouterlends. external flanges- 1 `which .abut against the .outer face .off the. pressure iplatevq, .the lhousingsJo'elng .inserted through iholes intheapressureplate, and thefpins 2 beingarrangedtopass through. the :inner ends of-the corresponding housings. f

The adjacent faces of .the `cam Vplate v and collar.. w. arefinterconnec'ted bywblunt V.shaped or .other vteeth. as :8 enti-leonel engaging. corresponding'recessesasll in.v the other, the said teeth and recesses. bein-g `so 'shapedI that relative angular .movementlinetvveen` the plate: and icollar .causes thee-plate tolslidelo'n the spindiea;

The spindlera is vformedxvvitli an axial 'bore l0, and through the bore passes a slidable thrust rod I I operable by the user and adapted at its outer end to exert endwise pressure on the center of the pressure plate q.

The mode of action of the clutch above de scribed is as follows:

When the pressure plate q is pushed outward by the rod I I against the action of the springs 3, endwise pressure on the friction plates r, z', y'. is relieved and the inner and outer clutch members e, b are thereby virtually disconnected from each other. On releasing the pressure exerted bythe rod II, the action of the springs 3 causes the pressure plate q to exert endwise pressure through reference characters sufxed by 2 in Figure in Figure 3.

the friction plate r on the friction plates i, :i and so enable the latter to effect a driving connection between the outer and inner clutch mem-` bers b, e. So long as the torque transmitted is a light one, the pressure exerted on the friction plates i, a' is solely that due to the springs 3, and no relative angular movement occurs between the cam plate 'u and cam collar w. But when the torque exceeds a predetermined amount,the cam plate v moves relatively to the cam collar w and causes the endwise pressure exerted on the fric' tion plates i, j by the springs 3 to be correspondingly increased.. v Y K v Compensation for wearof the frictionv pads VVe is effected by adjusting the screw collar 4 onthe stems 2.

vand the cam collar 104, the pressure on the friction members being increased'by relative angular movement of the cam plate and collar if the torque exceeds a predetermined amount. The sleeve l1 serves to prevent relative angular movement of the plates r4 and e4 without affecting the required relative axial movementsofvthese parts.

-By our' invention vwe are.;I able to vtransmit heavier torquesthan is ordinarily possible with a clutch of a given size, and We enableV the desired result to be obtained in a very simple manner.

Whilst Vthe invention is primarily intended for use, in motor cycle transmission mechanisms it may be applied to other analogous uses. The invention is 4not,rh: wever, limited to the examples Y above described as Vsubordinate details of con- Figures 3 to 5 illustrate two modified forms ofV the invention in which parts similar or analogous i to those above described are indicated by the same 3, and 4 in'Figures 4 and 5.

The embodiment shown in Figure 3 is distinv Vguished from that shownjin Figure 1 by the'forml and arrangement of j the driving (or driven) sprocket wheel and the friction plates. Thus, the sprocket wheel c2 is freely mounted on the spindle a2 ata position between and adjacent to a plate r2, Vformed Onprsecured to the pressure I member q2 and a plate e2 secured on the spindle. Alsor the'sprocket'wheel c2 andthe plates r2, e2

l are' adapted to serveasthe friction plates of the clutch, thin rings z2 of friction material being arranged between them. u f

` In the embodiment shown inFigures 4 and` 5, there is freely mounted on the spindlea4 at the y side lof the cam plate v4 remote from the cam collar 104 a short sleeve Il, and on this sleeve are mounted the sprocket wheel c4` and the friction l plate e4, the' sprocket wheel being rotatably supported by the sleeve, andthe friction plate being 1 splined to the sleeve and supported endwise by l a' shoulder 20 on the sleeve. At the side adjacent to the sleeve I1 the cam plate v4 is formed with a central boss 18, and the outer end of this boss isV formed with projections I9 which engage complementary recesses 2l in the adjacent end of I the sleeve soV that the sleeve is angularly 'movable- With but'permitsvindependent axial movel ment ofthe cam plate, the other end of the sleeve y being supported axially by a shoulder 22 on the spindle a4.

In other respects the embodimentA a plurality of springs acting ,onthe pressure member in theY direction for causing it to exert pressure on the plates, means adapted under the control of the user to act on the pressure member in the direction `forgcausingr it to` relieve pressure on the plates, `and a cam plate freely mounted on the spindle and slidably connected'to the pressu1'e1member,pinssurrounded by the-springs and secured to the cam plate, adjustable collars mounted on thepins and serving as ,abutments foradjacent ends of thesprings, tubular housings enclosing-,the springsand carried bythe shown in Figures 4 and 5 is similar to that lshown l When the clutch shown in Figures 4 and 5 is in operation, the action ofthe springs as 34 causes r endwise pressure to be exerted on the friction 1 membersv formed by the plate r4, the sprocket wheel e4 and the plate e4, and so enables a driving connection Vto be effected Vbetween the sprocket wheel and the spindle a4 through the pressure l member '(14, the pin or pins g4, the camplate o4,

pressure member, the said housings being provided with abutments for the other ends of 4the springs, and la camv collar rrotatablewith and.

supported ragainst'eridwise movement on the spin,- dle, the cam plate and collar having intrengagy ing end faces so shaped that relative angular movement Ybetween the cam plate and collar causes-,the cam plate to-slide on the spindle and thereby increase the pressure exerted vby the springs on the pressure member. f y

25A friction clutch as claimed in claim 1,'-in

which vthe friction plates are formed by the ro- Y tatable member to Vbe connected to thespin'dle, a second plate situated at one side'of the said member andA connected tothe cam plate, vandV a third,v plate situated at the other side of the said member and slidablyconnected to the cam plate.

` THOMAS HENRY BRIGGS.`

. WALTER; HENRY BRIGGS.

clutchfcomprising the combina- 

